遇到一個題目是求陣列的交集和並集，當時沒思考出來，現在靜下心來搞出來

package base0815_sendRedPacket;                                     
import java.util.ArrayList;                                         
                                                                    
public class Array {                                                
    public static void main(String[] args) {                        
        int [] array1 = {1,3,4,6,8,9,15};                           
        int [] array2 = {3,4,6,8,9,14};                             
                                                                    
        //求陣列的交集                                                    
        ArrayList<Integer> newList = new ArrayList<>();             
        for (int i = 0; i < array1.length; i++) {                   
            for (int i1 = 0; i1 < array2.length; i1++) {            
                if (array1[i] == array2[i1]){                       
                    newList.add(array1[i]);                         
                }                                                   
            }                                                       
        }                                                           
        //輸出交集                                                      
        System.out.println(newList.toString());                     
                                                                    
        //求陣列並集                                                     
        ArrayList<Integer> newList1 = new ArrayList<>();            
        for (int i = 0; i < array1.length; i++) {                   
            newList1.add(array1[i]);                                
        }                                                           
        for (int i = 0; i < array2.length; i++) {                   
             newList1.add(array2[i]);                               
        }                                                           
        for (int i = 0; i < newList.size(); i++) {                  
             newList1.remove(newList.get(i));                       
        }                                                           
        // 輸出並集                                                     
        System.out.println(newList1.toString());                    
                                                                    
    }                                                               
}